What is % Body Fat
When measuring fitness, one of the best tools to determine your fitness is the amount of body fat and the amount of lean mass that you have. The body needs fat for many metabolic functions but too much fat can cause health issues. Therefore, measuring the % of body fat is important. There is only way to truly measure how much fat we are carrying. It is to kill us and withdraw all the fat from our corpse! I have never had too many volunteer for this.
Hydrostatic Weighing
This method was the gold standard and requires being dunked in a tank of water and measuring the displacement. It is not very effective for the everyday person. Likewise the Hexa method and infrared methods are accurate but not affordable.
Using skin fold calipers to measure % body fat for men and women.
Skin fold measurement is a fairly easy and accurate method to determine your % body fat. I use the above caliper, which is about $19.00 on Amazon. There is an app on my i-pad called Body Tracker by Linear Software. The app allows me to input the measurements I get with the caliper and it does all the calculations. I use the Jackson/Pollock 3 site measurements and the sites to measure are different for men and women. For women the measurement sites are the triceps, suprailiac crest and the thigh. For men they are the chest, abdomen and thigh. The app also has diagrams and a video on how to take the measurement. Consistent use and practice with the calipers will give good results. I am able to measure my own sites but a woman would need help with the triceps measurement.
All % body fat measurements are approximations but of the three I will mention, this is the most accurate
I checked the app store and the Fitness Tracker app is no longer available. I contacted the company and they stated that they weren’t getting enough sales.
This isn’t a real issue as both the Jackson Pollock 3 site and the Navy Method described below are easy to find on the web where you can plug in your variables and get the results for free!
Navy Method (Tape Measure Method) for determining % body fat.
The above app also has a couple of other methods of determining % body fat, one which is the Navy Method. With this method, the sex, weight, height, neck measurement and waist measurements are input and it will give you an approximate % body fat measurement. I find this method gives an approximately 22% higher reading that the skin fold method. Both methods are only approximations though. Using this method can still give you a starting point and you can map your progress consistently
Fitness scale for measuring % body fat
There are many fitness scales on the market today that will measure your %body fat. They work by sending an electrical current up your leg and since fat and muscle are different densities, they are able to measure the impedance and come up with a % body fat number. The downfall with the scale is that you can get a different reading throughout the day depending on your hydration level. For instance, On Sept 1 when I used my scale first thing in the morning I was 227. 2 lbs and 28.8% body fat. (The skin fold showed 20.1 % and the Navy method 25.38%) I measured myself again at 5 pm, after eating and drinking all day and it showed I was 227.7 lbs and 21.6% body fat!
I use all three methods when I am measuring my % body fat and record all three but the one I use as the most accurate is the skin fold measurements. The other two are just for comparison purposes
Body Fat charts
| Age | 20-29 | 30-39 | 40-49 | 50-59 | 60+ |
| Female | 16-24% | 17-25% | 19-28% | 22-31% | 22-33% |
| Male | 7-17% | 12-21% | 14-23% | 16-24% | 17-25% |
The above chart will give you an idea on whether or not you are in the healthy range. There are other article on the web which will break these numbers down even further. If you are looking for the classic “six pack” you will need to be in lower numbers.
Tape measure for measuring
A cloth tap measure is required to measure your different body parts. You need to remember that muscle is denser than fat and if you are exercising and eating right then you should be losing fat and gaining muscle but you may not be losing weight. My body fat measurement was 20.1 % with a 42 inch waist on Sept 01. If I was at 15% body fat then for sure my waist would not be 42 inches but I could possible weigh the same if I put on muscle and lost the fat. Therefore it is important to weigh yourself but the tape measure will tell you if you are improving as will the % body fat.
I use the tape measure to record a number of different sites and record them in three places. The app I mentioned above records the measurements, I use a chart in a book which I then transfer to a spreadsheet.
Chart for recording measurements
What you record is up to you. I record the data I get from the scale, my measurements and the results of the % body fat measurements for both the skinfold and the Navy method. I will break my chart down into four charts so you can see what I measure
| Date | |
| Weight | |
| % BF | |
| % H2O | |
| Muscle (lean) | |
| Physique Rating | My scale rates this |
| BMR (Basic Metabolic Rate) | How many calories to maintain weight |
| Metabolic Age | This can be higher or lower than actual |
| Bone Mass | |
| Visceral Fat | dangerous fat around the internal organs |
| Chest in mm using skinfold caliper | |
| Stomach in mm using skinfold caliper | |
| Thigh in mm using skinfold caliper | |
| % Body Fat | |
| Lean Muscle weight | |
| Fat weight |
| Neck | |
| Chest | |
| Stomach at navel | |
| Hips at widest | |
| Right Thigh at largest spot | |
| Left Thigh as above | |
| Right Calf | |
| Left Calf | |
| Right bicep | |
| Left Bicep |
| Navy % Body Fat | |
| Lean Muscle | |
| Fat |